1. Field of the Invention
The present invention generally relates to liquid processing apparatuses, liquid processing methods and storage media. More specifically, the present invention relates to a liquid processing apparatus including a liquid processing unit configured to supply a chemical solution to a substrate so that a liquid process is performed, a liquid processing method, and a storage medium where a computer program for implementing its coating method is stored.
2. Description of the Related Art
Conventionally, in a photo resist process as one of semiconductor manufacturing processes, for example, resist liquid is coated on a surface of a substrate, a semiconductor wafer that will be referred “wafer” hereinafter so that a resist film is formed; the resist film is exposed with a designated pattern; and then the substrate is developed so that desired pattern is formed on the substrate.
Such a process is generally performed by using a system where an exposing apparatus is connected to a coating and developing apparatus configured to perform a coating process and a developing process.
Such a system is provided in a clean room. A down flow of air is maintained in this clean room in order to prevent particles from flying. The air is controlled so as to have the designated temperature and moisture content in order to prevent influencing on a process of the system.
In addition, in the above-mentioned coating and developing apparatus, various kinds of liquid processing apparatuses including a resist liquid coating unit, developing unit, or the like are provided. The resist liquid coating unit is configured to coat the above-mentioned resist liquid. The developing unit is configured to coat developing liquid so as to perform the above-mentioned developing process.
When the liquid process is applied to the wafer in each liquid process unit, it is necessary to maintain a process atmosphere of the wafer to be a designated atmosphere. Because of this, it is necessary to supply air whose temperature and moisture content are controlled to these liquid processing units.
Accordingly, a temperature and moisture control unit configured to take air of the designated atmosphere and perform temperature and moisture control of the taken air, a filter configured to clean the air whose temperature and moisture are controlled, and others are provided in the coating and developing apparatus. In addition, an air supplying part configured to supply the air, whose temperature and moisture content are controlled by the temperature and moisture control unit, to each liquid process unit is provided in the coating and developing apparatus.
If the difference of the temperature and moisture between the air before the temperature and moisture are controlled and the air after the temperature and moisture are controlled is large, the workload of the temperature and moisture control unit becomes large. In order to prevent generation of such a workload, it is normal practice that the air in the clean room where the temperature and moisture are controlled is taken by the air supplying part so that the temperature and moisture control is performed and the air is supplied to each liquid processing unit.
However, an apparatus for directly applying a process to the wafer such as the coating and developing apparatus or the exposing apparatus should be provided in a limited space of the clean room with a priority. Therefore, this air supplying part is frequently provided under the floor. It is necessary to provide an air supplying pipe and an air suction pipe under the floor. Here, the air supplying pipe is configured to supply the air in the clean room to the air supplying part. The air suction pipe is configured to supply the temperature and moisture controlled air from the air supplying part to the coating and developing apparatus.
As discussed above, the area of the clean room is limited. Under the floor of the clean room, not only the air supplying pipe and the air suction pipe but also a complex and large pipe system is provided. Gas or liquid for supplying power to the coating and developing apparatus flows in the pipe system. Accordingly, it may be necessary to provide the air supplying pipe and the air suction pipe through a small space formed between pipes of this pipe system.
In the meantime, recently, as the wafer size has become large, each processing unit in the coating and developing apparatus has become large. Furthermore, as the resist pattern to be formed becomes minute, it is necessary to perform the temperature and moisture control of the periphery of the wafer with high precision. Accordingly, it is considered to supply the temperature and moisture controlled air in not only the processing unit but also the conveyance area of the wafer between the processing units.
In this case, it is necessary for the air supplying part to supply a large amount of the air to the coating and developing apparatus. For example, while the temperature and moisture controlled air of 35 m3/minute should be supplied according to the conventional art, it is now required to supply the air at 70 m3/minute.
In addition, as the amount of the temperature and moisture controlled air to be supplied is increased, the amount of suction of the air in the clean room should be increased. Because of this, it is required to make the diameter of the air supplying pipe large.
Furthermore, it is considered to provide a heat insulation material in the periphery of the air supplying pipe in order to prevent the influence of outside air and control the temperature and moisture with high precision.
However, as discussed above, the complex pipe system is provided under the floor of the clean room. Accordingly, if the diameter is large and there is heat insulation material on the periphery of the air supplying pipe, the sizes of the air supplying pipe and the air suction pipe are large so as not to be provided between the space between the pipes of the pipe system. Hence, it may be difficult to provide the large size air supplying pipe and air suction pipe.
The length of the air supplying pipe and air suction pipe may be made large and plural portions of the air supplying pipe and air suction pipe may be curved so that the air supplying pipe and air suction pipe are provided with a space with the pipe system under the floor. However, if the air supplying pipe is too long and curved too much, it may be difficult to control the temperature and moisture and the amount of the air flowing into the pipe with high precision. As a result of this, a processing atmosphere of the wafer in the liquid processing unit may be influenced.
In addition, it is necessary to provide the air supplying pipe and the air suction pipe so that the air supplying pipe and the air suction pipe can be separated from not only the pipe system but also a beam or the like of a structure where the clean room is provided.
Thus, there may be an obstacle to providing the coating and developing apparatus with the air supplying pipe and the air suction pipe.
While a mechanism for supplying clean air to a resist coating apparatus and receiving the supplied air is discussed at paragraph 0045 of Japanese Patent No. 3375294, this mechanism does not solve the above-discussed problems. Furthermore, while a mechanism for individually controlling the atmosphere of each processing unit of a processing apparatus is discussed at paragraph 0021 and 0022 of Japanese Patent No. 3388706, this mechanism does not solve the above-discussed problems.